In order to protect health and maintain hygiene, a variety of environments require controlled and limited microbial growth. Such environments include temporary and permanent healthcare facilities, caregiver facilities (e.g. daycares, nursing homes, etc.) and households. When growth of potentially harmful microbes is not controlled/limited in these environments, the risk of infection and spread of disease increases. Infection and disease may compromise the health and safety of humans and/or animals occupying these environments. While potentially not as sensitive as the above-identified environments, workplace and public environments may also be negatively impacted by uncontrolled/unlimited growth of disease-causing microbes.
Some types of microorganisms (bacteria, viruses, fungi, etc.) are capable of negatively impacting the health and/or safety of living organisms. Such microorganisms can be transmitted by contact with surfaces on which the microorganisms are present and/or multiplying and by contact between humans/animals already infected with particular microorganisms. When such microorganisms spread and infect new “hosts”, the “host” can either go from an otherwise healthy state to a state of illness or from a “compromised” state (i.e. a state of pre-existing illness or a weak immune system) to a more serious/severe state. The public health impact of the undesired spread of microorganisms is significant as reflected by time out of school, time away from work (either for self or to care for others not able to care for themselves), additional time for which professional health care is needed, etc. Therefore, it is desirable to be able to prevent or inhibit microbial presence/growth on targeted surfaces. The presence of microorganisms can be eliminated/controlled using surface treatments that may be applied directly (as from a spray bottle) and by using wipes or other carriers that include the surface treatment. Further, it is desirable that such surface treatments have durability and persistence so that they do not need to be re-applied on a frequent basis.
There are many detergent, disinfectant, cleaning and antimicrobial compositions known in the art for killing and preventing growth of microorganisms. Those compositions include components/ingredients that are well-known for antimicrobial functionality. For example, quaternary ammonium compounds are considered “broad spectrum” antimicrobial cationic compounds that are effective against both Gram positive (e.g. Staphylococcus species) and Gram negative (e.g. Escherichia coli) microorganisms. Other components/ingredients that may be incorporated into products for removing/reducing microorganisms on surfaces include alcohols, acids and bleaching agents, such as hydrogen peroxide. Not all of the antimicrobial components can be used at the same time because some of them form unstable combinations.
Disinfecting and cleaning compositions that provide antimicrobial activity over a period of time are also known in the art. For example, U.S. Pat. No. 6,270,754 issued to Zhou et al. and entitled “Antimicrobial Cleaning Composition” (hereinafter “the '754 patent”) is directed to an antibacterial cleaning composition that exhibits germicidal activity for sustained periods of time. The '754 patent discloses an aqueous cleaning composition that includes a quaternary ammonium compound, an anionic polymer (where the anionic polymer has an acid number greater than 10 and the anionic polymer is partially or completely neutralized by the quaternary ammonium compound to form a polymer complex), a dispersing agent and/or a water-miscible solvent. The aqueous cleaning composition of the '754 patent has antibacterial activity against both Gram positive and Gram negative bacteria. However, the components of the '754 patent may not be effective against a broader range of microorganisms, such as non-enveloped viruses.
In addition to the composition of the '754 patent, there are compositions known in the art that are effective against a broad spectrum of microorganisms and continue to have activity for a period of time. For example, U.S. Pat. No. 7,598,214 issued to Cusack et al. and entitled “Disinfecting Compositions Containing A Polymer Complex Of an Organic Acid” (hereinafter “the '214 patent”) is directed to compositions that include at least one organic acid and at least one polymer capable of forming a complex with the at least one organic acid. The compositions of the '214 patent may also optionally include an anionic surfactant and an organic solvent. The organic acid may be citric acid and examples of suitable polymers include vinylpyrrolidone/dimethylaminoethylmethacrylate copolymer, vinylpyrrolidone/vinylacetate copolymers, vinylpyrrolidone/vinylcaprolactum/ammonium derivative terpolymers and polyvinylpyrrolidone. The compositions of the '214 patent need an organic solvent and they are pH sensitive. Because of the acid-based reaction between the polymer having a tertiary amine functionality and the organic acid, the compositions are not effective in higher pH environments. In a higher pH environment, the reaction would reverse and the polymer would be rendered ineffective because it would be neutral. Though the compositions of the '214 patent are effective against a broader spectrum of microorganisms, the compositions may not be effective against the spore-form of all microorganisms because the compositions cannot penetrate through the outer wall of the spores.
While many antimicrobial compositions are known and while some of those compositions maintain their antimicrobial activity over a period of time, there remains a need in the art for a durable antimicrobial composition that is effective against a broad range of microorganisms, including the spore-form of potentially harmful microorganisms. Additionally, there remains a need for a durable antimicrobial composition that is stable (i.e. is not reactive) so that it is not unnecessarily harsh (causing wear or corrosion) on the surfaces on which it is used. Further, there remains a need for a durable antimicrobial composition that does not require a volatile solvent that may have an unpleasant smell.